Hi sonle2001,
First off, I'm sorry to hear about your father. I wish the best for his recovery.
As for the ticket, make sure you write down the ticket numbers. If the tickets have a SkyMiles number attached, the cancelled tickets should show up in the "My Wallet" section of the website (it can be hard to find where that is, but keep clicking around). If you find it there, it should show you the remaining value of the ticket. That's usually what you paid minus the change fee (that fee may be up to $450 for an international fare). If there's still value remaining, you can use that for a future ticket for the person who originally booked the flight - but it expires one year after the date which you purchased it.
When I had to cancel a ticket due to a medical issue, the phone agent added a note to the ticket that the change fee should be waived. It still shows up in "My Wallet" minus the change fee, but if I call in, the ticket agent should see the note and apply the full value.